1. Field of the Invention
This invention relates to a method of cleaning a large storage container of clean water, more particularly this invention relates to a method of cleaning a large storage tank of clean water and even more particularly this invention relates to a method of cleaning a large storage tank of drinking water.
2. Brief Description of the Prior Art
Clean water has been stored by various large storage techniques such as ponds, lakes, reservoirs, cisterns, tanks, etc. for various reasons as an integral part of a water system. These reasons include water usage, source variance, energy availability, gravity flow, gravity pressurization, fire fighting, blackouts, and other emergency situations. Of all the storage techniques, tanks are the best in terms of convenience, protection against contamination, shielding from sunlight, and ease in determining the amount of water stored.
For high water quality control and for insurance of the integrity of its container, it is necessary to perform periodic cleaning of the container. In the bottom of all of these storage means gunk and muck will accumulate coating its bottom. An open container or a poorly covered one will always allow dirt, leaves, insects, lizards, and mice into the water system. The incoming water into the storage container may carry its own sediment, held in suspension, which, in the tranquil waters of the tank, will precipitate. Some minerals as well will, upon contact with air, precipitate out in the storage container. Many times deteriation of the container or its coating or liner can cause sediment in the bottom of the container and/or contaminate the water or cause it to be distaseful or discolored.
Because of the importance in avoiding dirtying or contaminating the water, the most convenient and primary storage containers have been difficult to clean while they contain a large amount of water. By primary container it is meant one that contains water that requires no treatment before use. The large size of the container and the fear of disturbing sediment and deposists on the bottom and walls of the container have made cleaning the interior of a filled container impractical. Consequently, heretofore, these containers had to be emptied before a thorough cleaning could be done. However it is undesirable to completely empty such a container because of the need of a temporary means of holding the water. If the water is disposed of during the cleaning, water is not available for emergency use.